"Perfect" albums
Pink Floyd - Animals
Yeah, only five songs and two are nearly the same, but it's perfect.
Actually, "Dogs", and " Sheep" are more fully worked out, lyrically mature, and articulate final versions of bits and pieces of previous PF songs the group had been rehearsing and playing live for a few years called, "You Gotta be Crazy" and " Raving and Drooling" where actual lyric stanzas from these songs are on those previously mentioned songs on Animals. The music is far more harder, intense, and has less fluid textures you see on DSOM and Wish You Were Here, but more strident in its focus and album themes overall.
I've said it on SR before and I'll say here it again, Animals was probably the gradual but likely inevitable start of Pink Floyd's music/lyrical and album themes being more a vehicle for Roger Waters ideas and feelings towards organized religion, ruthless unfettered capitalism, morally vacant and disreputable yet "holier-than-thou" moral crusaders who are in actuality the worst type of hypocrites possible.
Roger Waters probably would be the first to say Animals wasn't his best, most creative PF album in terms of his lyrical contribution, overall socio-political themes and commentary at least compared to the Wall, to a lesser extent The Final Cit and some of his later solo albums, the characters, songs, and images are somewhat crude in how their portrayed and expressed, by comparison.